In constructing an electrical circuit, certain types of electrical devices such as relays, timers and counters are often connected to the circuit via sockets, acting as intermediary components between the electrical devices and the rest of the circuit. Using sockets to connect devices in a circuit facilitates the removal and addition of electrical devices within the circuit, such as when upgrading to an electrical device of a different power rating or when replacing a defective electrical device.
A socket typically includes socket terminals such as leads or wires for electrical connection to other components in the circuit. In practice, an electrical device may first be inserted in an appropriate socket. Internal electronics or circuitry of the socket may enable electrical connection of the inserted device to the socket terminals, which in turn are appropriately connected to an external circuit, so that the inserted device is electrically connected to the external circuit. The sockets may be appropriately fastened, for example by screws, to an appropriate support surface such as a circuit board.
In some cases, it may be necessary for a number of electrical devices inserted in nearby sockets to share a single voltage signal or voltage source. Over the past this has been achieved by using additional wires or jumpers between terminals of different sockets so that the devices are connected in parallel to one another, and therefore connected in parallel to the same voltage signal or voltage source. Installing additional wires or jumpers to connect a large number of electrical devices in parallel may be time-consuming or prone to errors. Similarly, disconnecting electrical devices from the parallel circuit may also be time-consuming.